/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: #0a0a0a;
  background: #fafaf7;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, p, ul, dl, dd { margin: 0; padding: 0; }
ul { list-style: none; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; border: 0; background: none; }
em { font-style: italic; font-family: "Times New Roman", "Songti SC", serif; font-weight: 400; }

.container { max-width: 1180px; margin: 0 auto; padding: 0 28px; }
.hairline { border: 0; border-top: 1px solid #e8e6df; margin: 0; }
.hide-sm { display: inline; }

/* ===== Breadcrumb ===== */
.crumb {
  background: #f5f3ec;
  border-bottom: 1px solid #e8e6df;
  font-size: 13px;
  color: #888;
}
.crumb .container { padding-top: 12px; padding-bottom: 12px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.crumb a { color: #555; }
.crumb a:hover { color: #0a0a0a; text-decoration: underline; }
.crumb span { color: #bbb; }

/* ===== FAQ ===== */
.faq-list { display: grid; gap: 14px; }
.faq-item {
  background: #fff;
  border: 1px solid #e8e6df;
  border-radius: 16px;
  padding: 4px 28px;
  transition: border-color 0.2s;
}
.faq-item[open] { border-color: #0a0a0a; }
.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  list-style: none;
  cursor: pointer;
  padding: 20px 0;
  gap: 16px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary h3 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.005em;
  margin: 0;
  flex: 1;
}
.faq-item summary i {
  font-style: normal;
  font-size: 22px;
  color: #888;
  transition: transform 0.25s;
  line-height: 1;
}
.faq-item[open] summary i { transform: rotate(45deg); }
.faq-item p {
  font-size: 15px;
  color: #555;
  line-height: 1.8;
  padding: 4px 0 22px;
  border-top: 1px solid #f0eee5;
  margin-top: -4px;
  padding-top: 18px;
}
.faq-item p a { color: #0a0a0a; text-decoration: underline; text-underline-offset: 3px; }
.faq-item p strong { color: #0a0a0a; }

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 247, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid #e8e6df;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 24px;
}
.logo { display: inline-flex; align-items: center; gap: 8px; font-weight: 600; font-size: 17px; }
.logo-mark {
  width: 22px; height: 22px;
  background: #0a0a0a;
  border-radius: 6px;
  position: relative;
}
.logo-mark::after {
  content: "";
  position: absolute;
  inset: 5px;
  border: 2px solid #fafaf7;
  border-radius: 50%;
  border-right-color: transparent;
}
.logo-text .dot { color: #6b7a3a; margin-left: 2px; }

.nav-menu { display: flex; gap: 32px; }
.nav-link {
  font-size: 14px;
  color: #555;
  transition: color 0.2s;
}
.nav-link:hover { color: #0a0a0a; }

.nav-right { display: flex; align-items: center; gap: 18px; }
.nav-secondary { font-size: 14px; color: #555; }
.nav-secondary:hover { color: #0a0a0a; }

.nav-toggle {
  display: none;
  font-size: 24px;
  line-height: 1;
  padding: 4px 8px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 500;
  border-radius: 999px;
  transition: all 0.2s;
  white-space: nowrap;
}
.btn-dark { background: #0a0a0a; color: #fafaf7; }
.btn-dark:hover { background: #222; transform: translateY(-1px); }
.btn-line { border: 1px solid #0a0a0a; color: #0a0a0a; }
.btn-line:hover { background: #0a0a0a; color: #fafaf7; }
.btn-link { color: #0a0a0a; padding-left: 0; padding-right: 0; }
.btn-link:hover { text-decoration: underline; }
.btn-lg { padding: 14px 26px; font-size: 15px; }
.btn-block { display: flex; width: 100%; }

/* ===== Hero ===== */
.hero { padding: 88px 0 96px; }
.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: #f0eee5;
  border: 1px solid #e2dfd4;
  border-radius: 999px;
  font-size: 13px;
  color: #555;
  margin-bottom: 32px;
}
.dot-green {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #6b9d3a;
  box-shadow: 0 0 0 4px rgba(107, 157, 58, 0.15);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse { 50% { box-shadow: 0 0 0 7px rgba(107, 157, 58, 0); } }

.hero-title {
  font-size: clamp(48px, 7.5vw, 96px);
  line-height: 1.02;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
}
.hero-sub {
  font-size: 18px;
  line-height: 1.7;
  color: #444;
  max-width: 620px;
  margin-bottom: 36px;
}
.hero-cta {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 72px;
  flex-wrap: wrap;
}

.hero-meta {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  padding-top: 36px;
  border-top: 1px solid #e8e6df;
}
.meta { display: flex; flex-direction: column; gap: 6px; }
.meta-key { font-size: 13px; color: #888; }
.meta b { font-size: 24px; font-weight: 500; letter-spacing: -0.01em; }

/* ===== Section ===== */
.panel { padding: 96px 0; }
.section-head { margin-bottom: 56px; max-width: 720px; }
.eyebrow {
  display: inline-block;
  font-size: 13px;
  color: #6b7a3a;
  margin-bottom: 16px;
  font-weight: 500;
  letter-spacing: 0.02em;
}
.section-title {
  font-size: clamp(36px, 5vw, 60px);
  line-height: 1.08;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
.section-sub {
  font-size: 17px;
  color: #555;
  line-height: 1.7;
}

/* ===== Download grid ===== */
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}
.download-card {
  background: #fff;
  border: 1px solid #e8e6df;
  border-radius: 18px;
  padding: 32px 24px;
  text-align: center;
  transition: all 0.25s;
}
.download-card:hover {
  transform: translateY(-4px);
  border-color: #0a0a0a;
  box-shadow: 0 16px 40px rgba(10, 10, 10, 0.06);
}
.dl-icon {
  font-size: 40px;
  line-height: 1;
  margin-bottom: 16px;
  color: #0a0a0a;
}
.download-card h3 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.download-card p {
  font-size: 13px;
  color: #777;
  margin-bottom: 20px;
  line-height: 1.6;
}

/* ===== Form card ===== */
.form-card {
  background: #fff;
  border: 1px solid #e8e6df;
  border-radius: 22px;
  padding: 36px 40px;
  margin-top: 32px;
}
.form-tip {
  font-size: 14px;
  color: #666;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid #f0eee5;
}
.form-tip b { color: #0a0a0a; }

/* ===== Bullets ===== */
.bullets { display: grid; gap: 14px; }
.bullets li {
  display: flex;
  gap: 14px;
  font-size: 15px;
  color: #333;
  align-items: baseline;
}
.bullets li span {
  font-size: 12px;
  font-weight: 500;
  color: #6b7a3a;
  min-width: 22px;
}

/* ===== Feature grid ===== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid #e8e6df;
  border-left: 1px solid #e8e6df;
}
.feature-item {
  padding: 36px 32px;
  border-right: 1px solid #e8e6df;
  border-bottom: 1px solid #e8e6df;
  background: #fff;
}
.feature-num {
  font-size: 12px;
  color: #6b7a3a;
  font-weight: 500;
  margin-bottom: 24px;
}
.feature-item h3 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
}
.feature-item p {
  font-size: 14px;
  color: #666;
  line-height: 1.7;
}

/* ===== Node grid ===== */
.node-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid #e8e6df;
  border-left: 1px solid #e8e6df;
}
.node-cell {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 24px;
  border-right: 1px solid #e8e6df;
  border-bottom: 1px solid #e8e6df;
  background: #fff;
  font-size: 14px;
}
.node-cell span { color: #555; }
.node-cell b { font-weight: 500; color: #6b7a3a; }
.node-foot {
  font-size: 13px;
  color: #888;
  margin-top: 20px;
  text-align: center;
}

/* ===== Price grid ===== */
.price-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}
.price-grid-3 { grid-template-columns: repeat(3, 1fr); }
.price-card {
  background: #fff;
  border: 1px solid #e8e6df;
  border-radius: 22px;
  padding: 36px 32px;
  position: relative;
  transition: all 0.25s;
  display: flex;
  flex-direction: column;
}
.price-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(10, 10, 10, 0.06);
}
.price-card-hot {
  border-color: #0a0a0a;
  border-width: 2px;
  background: #0a0a0a;
  color: #fafaf7;
}
.price-card-hot .price-tag { background: #6b9d3a; color: #fff; border-color: #6b9d3a; }
.price-card-hot .price-desc { color: #aaa; }
.price-card-hot .btn-line { border-color: #fafaf7; color: #fafaf7; }
.price-tag {
  display: inline-block;
  align-self: flex-start;
  padding: 4px 12px;
  font-size: 12px;
  color: #6b7a3a;
  border: 1px solid #d6dab8;
  background: #f4f5e9;
  border-radius: 999px;
  margin-bottom: 22px;
}
.price-amount {
  font-size: 44px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1;
  margin-bottom: 8px;
}
.price-amount span {
  font-size: 14px;
  font-weight: 400;
  color: inherit;
  opacity: 0.6;
  margin-left: 8px;
}
.price-energy {
  font-size: 14px;
  color: inherit;
  opacity: 0.75;
  margin-bottom: 18px;
}
.price-desc {
  font-size: 14px;
  color: #666;
  line-height: 1.7;
  flex: 1;
  margin-bottom: 24px;
}

/* ===== About ===== */
.about .section-head { margin-bottom: 40px; }
.about-content {
  max-width: 720px;
  margin-bottom: 56px;
}
.about-content p {
  font-size: 17px;
  line-height: 1.8;
  color: #333;
  margin-bottom: 18px;
}
.meta-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid #e8e6df;
}
.meta-list > div {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 24px;
  padding: 22px 0;
  border-bottom: 1px solid #e8e6df;
  font-size: 15px;
}
.meta-list dt { color: #888; }
.meta-list dd { color: #222; margin: 0; }

/* ===== Contact ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.contact-card {
  background: #fff;
  border: 1px solid #e8e6df;
  border-radius: 22px;
  padding: 32px;
}
.contact-key {
  display: inline-block;
  font-size: 12px;
  color: #6b7a3a;
  margin-bottom: 18px;
}
.contact-card h3 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
  word-break: break-all;
}
.contact-card p {
  font-size: 14px;
  color: #666;
  margin-bottom: 22px;
}

/* ===== Footer ===== */
.footer { padding: 72px 0 36px; background: #f5f3ec; }
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-brand p { font-size: 14px; color: #777; margin-top: 16px; line-height: 1.7; }
.footer-col h4 {
  font-size: 13px;
  font-weight: 500;
  color: #999;
  margin-bottom: 18px;
  letter-spacing: 0.04em;
}
.footer-col ul li {
  font-size: 14px;
  color: #444;
  margin-bottom: 12px;
}
.footer-col a:hover { color: #0a0a0a; text-decoration: underline; }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 28px;
  border-top: 1px solid #e2dfd4;
  font-size: 13px;
  color: #888;
}
.footer-bottom .status { display: inline-flex; align-items: center; gap: 8px; }

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #0a0a0a;
  color: #fafaf7;
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 14px;
  opacity: 0;
  pointer-events: none;
  transition: all 0.25s;
  z-index: 1000;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===== Responsive ===== */
@media (max-width: 960px) {
  .nav-menu, .nav-secondary { display: none; }
  .nav-toggle { display: inline-block; }
  .nav-menu.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: #fafaf7;
    border-bottom: 1px solid #e8e6df;
    padding: 16px 28px 24px;
    gap: 14px;
  }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .node-grid { grid-template-columns: repeat(2, 1fr); }
  .price-grid, .price-grid-3 { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 36px; }
  .meta-list { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .container { padding: 0 20px; }
  .hide-sm { display: none; }
  .hero { padding: 56px 0 64px; }
  .panel { padding: 64px 0; }
  .hero-meta { grid-template-columns: repeat(2, 1fr); gap: 22px; }
  .download-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .node-grid { grid-template-columns: 1fr; }
  .form-card { padding: 24px 22px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; gap: 12px; }
}